It is known in the field of laser research that all laser systems are limited in the amount of power that can be extracted from a single optical resonator. Accordingly, workers in the field have attempted to scale-up in power by combining a number of laser resonators or amplifiers to form a single output beam. Among the many approaches that have been tried, the MOPA (Master Oscillator Power Amplifier) is applicable to multiline, multimode operation. However, the mode control and extraction efficiency of amplifiers is in general inferior to that of oscillators, resulting in a poorer efficiency of the overall system. It is also known to use injection locking of a number of resonators locked to a single master oscillator. The locking range for such a system is very narrow when the system is configured to provide good mode control and extraction efficiency. It is also known to couple radiation between resonators, where several cavities share a common element or otherwise overlap. All of the prior art approaches have different drawbacks that limit the amount of power that can be provided.